The Pentagon confirmed Wednesday that Islamic State in Iraq and Syria (ISIS) fighters took possession of a stray bundle of U.S.-airdropped weapons and other supplies in the Syrian border town of Kobani earlier this week.
The U.S. had dropped 28 bundles filled with grenades, mortar rounds and other supplies intended for Kurdish fighters in Kobani battling ISIS, but at least one had gone astray and was immediately destroyed.
However, Pentagon officials confirmed a second one had gone off course and ended up in enemy hands. A YouTube video uploaded on Tuesday appeared to show an ISIS militant going through an array of boxes, at least two of which contained grenades.
"There's always going to be some margin of error" when airdropping supplies, Warren added. "Wind can cause a parachute to move off its intended target."
Warren said there was no evidence that other bundles ended up in enemy hands and that the issue is not "of any real concern to us." He suggested that one bundle would not give ISIS any significant advantage.
Warren said the United States had decided to airdrop the supplies, since bringing them to Kurdish fighters on the ground is "far more dangerous."
Defense officials said Tuesday that Kobani, a northern Syrian town near Turkey, was still contested, but that Kurdish fighters controlled a majority of the town.
While the Kurdish fighters have not retaken any ground from ISIS, they have halted ISIS's advance there over several days, Defense officials said.